The principal varieties of Pasta Filata cheese are mozzarella, scamorze and provolone. Pasta Filata cheeses, sometimes referred to as Italian cheese, are characterized as being prepared by a process that includes the step of immersing the curd in hot water or hot whey and working, stretching and molding the curd while it is in a plastic condition. A conventional method for the manufacture of Pasta Filata cheese, such as mozzarella, is described in Kosikowski, F., Cheese and Fermented Milkfoods, 1966, Edwards Brothers, Inc., Ann Arbor, Mich. (pp. 162-167). In the method described by Kosikowski, standardized milk is pasteurized and cooled to a temperature of about 90.degree. F. A starter culture is added with sufficient rennet to coagulate the milk in about thirty minutes. The resulting coagulant is cut to provide pieces of curd in whey. The cut curds are set in the warm whey for about fifteen minutes with periodic gentle agitation. The curds in the whey are pushed to the back of the vat and the free whey is removed from the vat. Whey removal is slower than that for cheddar cheese because of a lack of cooking and acidity. As the whey departs, the curds are packed gently together. The large curd packs are cut into blocks to effect quicker cooling. The curd blocks are rinsed with cold water and immersed in cold water. The cold water is drained after fifteen minutes and the curds are bundled into clean cheese cloth to make 45- to 60-lb. bundles. The curd bundles are placed in a chill room (40.degree. F.) to effect further draining of curd. The whey drains from the curd bundles overnight in the chill room. The curd, at this point, is referred to as raw curd. The drained curd bundles are removed from the chill room and acid ripening is commenced by exposing the drained curd bundles to warmer room temperatures for a period of at least one day. The curd bundles are removed from the warm room after complete drainage and after the cur pH decreases to a level of 5.2 to 5.4.
The cloth is removed from the acidified raw curd and the curd bundle is chopped into small pieces. These pieces are placed in hot water or hot whey, about 180.degree. F. in a mechanical blender. The hot water covers all the curd by a few inches. The curds are left in the hot water for a few minutes but not long enough for them to exceed a temperature of 135.degree. F. A gentle molding agitation is then started with a mechanical apparatus which is used to pull and stretch the raw curd into a smooth, white plastic mass. The hot plastic mass is packed into suitable molds. Later, the cheeses are immersed in a salt brine for a period of about twenty-four hours. The cheese is then dried in air and is wrapped and packaged for shipment.
It is apparent from the above description that considerable handworking of the cheese curd is required. It is also apparent that the process is complicated and subject to control problems. Numerous attempts have been made to provide improved methods for the manufacture of Pasta Filata cheese wherein the working and stretching of the raw curd is subplanted by continuous mechanical methods. U.S. Pat. No. 3,692,540 to Mauk describes a method for the manufacture of Pasta Filata cheese wherein the curd is held in whey to acid condition the curd. The curd is held until the acidity of the whey is from 0.25 to 0.30%. The raw curd is divided into pieces and the curd pieces are heated without working in a process cheese cooker to a temperature of 130.degree.-160.degree. F. The method of the Mauk patent utilizes a final direct heating step without working or stretching the cheese curd.
U.S. Pat. No. 3,117,008 to Mauk teaches a method for the manufacture of Pasta Filata-type cheeses wherein final curd texture is achieved by curing the curd for a period of time sufficient to provide a cheese having a smooth and continuous texture. In the method, a Pasta Filata curd, which includes acid-producing agents, is cooked at a temperature below that at which the acid-producing agents are substantially inactivated. Thereafter, the curd is leached to remove acid and provide an acidity of less than about 0.8%. The curd is then pressed and the pressed curd is subjected to vacuum conditions to close the curd. Thereafter, the curd is cured and the curing process provides a cheese having a smooth and continuous texture through the development of acidity by the acid-producing agents.
U.S. Pat. No. 3,531,297 to Kielsmeier, et al. is directed to a process for making Pasta Filata cheese wherein Pasta Filata cheese curd is subjected to particular treatment to make it more suitable for the steps of the Pasta Filata cheese-making process which follow cheddaring. The Pasta Filata cheese steps which follow cheddaring include heating the curd particles by contact with heated water to a temperature in the plastic temperature range of the curd while mixing and stretching the curd. The Kielsmeier, et al patent teaches that the mixing and stretching may be continued under superatmospheric pressure while forcing the curd through a restricted backpressure-creating outlet.
While the methods of the above-described patents are an improvement over the conventional method for the manufacture of Pasta Filata cheese, it would be desirable to provide a method for making Pasta Filata-type cheeses wherein an extended shelf life can be established.
Accordingly, it is an object of the present invention to provide an improved method for making Pasta Filata cheese. It is another object of the present invention to provide a method for making Pasta Filata cheese that extends the shelf life of the cheese. It is a further object of the invention to provide a method for making Pasta Filata cheese that is simple and economical and which lessens the amount of handworking of the curd.